Polarization-dependent XANES study of Bi2Sr2Ca1-xPrxCu2O8-delta insulatingsingle crystal

Pr doping has been extensively studied in cuprate superconductors to unders tand the mechanism of quenching of superconductivity in cuprate perovskites . Experience has revealed that it acts differently in different cuprate per ovskites. We have made high resolution polarization XANES measurements on a Pr-doped single crystal within the ab-plane on the Cu K and Pr L (III) abs orption edges to ascertain the valence state of Pr cation and thereby try l earning how it is quenching superconductivity in the present case. Our resu lts show that besides the Pr quenching holes the possibility of its localiz ing some holes through hybridization with O 2p and Cu 3d cannot be ruled ou t.